<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>学习flask首页</title>
</head>
<body>
    {% if username == 'Jacky' %}
        <p>Jacky学习flask的过程</p>
    {% else %}
        <p>不是Jacky</p>
    {% endif %}

    {% if age >= 18 %}
        <p>18周岁法定成年人</p>
    {% else %}
        <p>小于18周岁未成年</p>
    {% endif %}
</body>
</html>